Flow past an inclined spheroid in homogeneous and stratified environments

Abstract

Large-eddy simulations (LES) are performed to study the flow past a 6:1 prolate spheroid placed at an angle of incidence of $\alpha = 10^{\circ}$. The diameter-based Reynolds number ($Re = U_{\infty}D/\nu$) is set to a value of $5\times10^{3}$ and four values of diameter-based Froude numbers ($Fr = U_\infty/ND$) are analyzed: $Fr = \infty, 6, 1.9,$ and $1$. Visualizations of coefficient of pressure ($C_p$) and friction ($C_f$) contours reveal asymmetry in the $Fr = \infty$ and $6$ flows while, at $Fr = 1$ and $Fr = 1.9$, the flow over body does not have any visible asymmetry. This finding is further corroborated through the analysis of force coefficients on the body. The changes in the pressure coefficients ($C_p$), friction coefficients ($C_f$), and drag coefficients ($C_d$) with the Froude number are described in detail for $\alpha = 10^{\circ}$. We also present the analyses of forces on the body at $\alpha = 0^{\circ}$ angle of incidence for comparison with the $\alpha = 10^{\circ}$ cases.